Metcalfe on Ethernet’s lessons, unsung heros

"There's an army of unsung engineers who helped invent Ethernet," says Bob Metcalfe, taking a long drag on his cigarette as he ruminates about the now ubiquitous network technology he described in a memo to colleagues at Xerox PARC on May 22, 1973.

“There’s an army of unsung engineers who helped invent Ethernet,” says Bob Metcalfe, taking a long drag on his cigarette as he ruminates about the now ubiquitous network technology he described in a memo to colleagues at Xerox PARC on May 22, 1973.

As the smoke curls around his head some of the names and the stories begin to emerge from the distant past. The first is David Boggs, a Stanford grad student who in 1973 was working in the next lab over from Metcalfe at PARC.

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David Boggs

“Boggs noticed I had trouble skinning and soldering connectors at end of cables and offered to help because it was something he was good at,” Metcalfe recalls.

By 1976 the two men along with another lab partner, Tat Lam, created the first prototype of what was to become Ethernet, a 2.94 Mbit/second link over a coaxial cable.

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Ethernet 3 Mbit/s prototype

Lam was an analog engineer working on a bit-mapped display in the same basement of Building 34 as Metcalfe and Boggs. He helped create the transceiver for the prototype. Later Tam created a company that sold Ethernet transceivers and bore his initials, TCL, before disappearing from Metcalfe’s sight like so much cigarette smoke.

Note: Bob Metcalfe says he does not smoke and never has. The interview was conducted via phone and the reporter mistakenly thought he heard sounds of smoking.

So via email, Bob Metcalfe tells me:
"THANKS! for your interview of me, which is great, except for one thing: I DO NOT SMOKE AND NEVER HAVE."
My mistake: The interview was done as a telecon and I thought I heard the sounds of Bob smoking and imagined the smoke, etc. My apologies!

Although Metcalfe said it, I'm afraid the point gets lost in translation, almost always. What survived of Ethernet are really only two things: the name itself, and the format of the basic frame. That's it! In fact, there are more fancy IEEE variants of that basic frame now, still using the Ethernetr name.
Ethernet borrowed from other concepts, to keep itself viable. As speed increased, Ethernet dropped the shared bus medium and CSMA/CD protocol and adopted the rapid frame switching and full duplex links of ATM. (CSMA/CD is still there, but if used at all, it's only for a short point-to-point hop between one host and one switch port. Hardly what it was designed for!)
For the really fast interfaces, it adopted the optical transceivers of SONET.
And as Metcalfe said, it stayed strictly at layer 1 and 2, letting Internet Protocol (IP) take care of global routing between local networks. Where for example, ATM had its own global addressing and routing mechanisms, vying for the same roles as IP routing.
I think that the success of IP and packet switching, and the way Ethernet adopted techniques from other layer 1 and 2 network designs (the good ideas, leaving the not-so-good ideas behind), is what truly kept the Ethernet name alive.
It comes down to this: Ethernet, through all of its transformations, has always been "friendly to Internet Protocols." Much as SONET was friendly to ATM. So the true success story here is the way packet switching has pretty much come to dominate communications, taking over what used to be only circuit-switched networks or even virtual circuit networks. Ethernet and IP have been riding that packet switching wave together.